Alkali metal salts of oxygen acids tetravalent sulfur and metal complexing agents inan acidic dyebath and polyamide dyeing therewith



United States Patent 3,363,970 ALKALI METAL SALTS OF OXYGEN ACIDS TET- RAVALENT SULFUR AND METAL COMPLEX- ING AGENTS IN AN ACIDIC DYEBATH AND POLYAMlDE DYEING THEREWITH Karl Schalfner, Ramlingsburg, Basel-Land, and Charles Soiron, Riehen, Switzerland, assignors to J. R. Geigy A.G., Basel, Switzerland No Drawing. Filed Nov. 27, 1964, Ser. No. 414,444 Claims priority, application Switzerland, Nov. 29, 1963, 14,624/63 13 Claims. (Cl. 8-19) ABSTRACT OF THE DISCLOSURE Applicants dye and bleach wool and synthetic polyamide fibers with an acid dye solution containing alkali metal salts of the oxygen acids of tetravalent sulfur, e.g. alkali metal bisulfites and hydrogen pyrosulfites, and a metal complexing agent such as polymetaphosphates and aminocarboxylic acids such as ethylene diamine tetracetic acid.

The present invention concerns a process for the simultaneous dyeing and bleaching of polyamide fibers, the dye liquor used for this purpose as well as, as industrial products, the polyamide fiber materials such as wool, dyed and bleached according to this process or with this dye liquor.

In order to give wool dyeings in light to medium shades, particularly pastel shades, a purer and more brilliant appearance, it is necessary first to bleach the wool before dyeing. This bleaching requires a great deal of time and apparatus as, in general, the wool has to be treated in two different baths. In addition, many bleaching agents must be used in an alkaline medium which can injure the quality of the wool.

There have thus been many attempts to find methods of dyeing and bleaching wool in a single bath which can be performed, if possible, in a neutral or acid medium. However, because of the expense involved, the toxicity and the effect of the reactants used to influence the pH of the liquor, the method used up to the present has not always been completely satisfactory.

A process has now been found which enables polyamide fibers, in particular wool, to be dyed and bleached in a single bath while avoiding the disadvantages mentioned above.

The process according to the invention comprises treating the polyamide fiber material with a dye liquor which contains Water-soluble dyestutf, a water-soluble, preferably colorless, salt of an oxygen acid of tetravalent sulfur, a compound which is capable of forming stable, water-soluble, colorless complexes with certain metal ions, present in said dyebath, which are detrimental to the dyeing effect, as well as, optionally, salts known as coupage.

Hithereto water-soluble hydrogen sulfites as representatives of the salts of an oxygen acid of tetravalent sulfur as defined have already been used as bleaching agents, but their action is relatively slight. In addition, because of their reducing properties, many of them tend to decompose the dyestuif. This decomposition of the dyestuff, which is a great disadvantage, is often considerably increased by certain metal ions, especially heavy metal ions such as iron ions and the like, which are very often present in technical dye liquors. The source of these metal ions may be the water used for the preparation of the dyebath or one or several of the ingredients thereof. Such metal ions are referred to hereinafter in the specification as well as the appended claims as detrimental metal ions.

Compounds which form stable, water-soluble, colorless complexes with metal ions are added to the dye liquor in order to bind these detrimental metal ions. Surprisingly, these complex-forming agents have an unexpectedly additional, technically very desirable effect; they increase the color-improving property of the watersoluble salts of tetravalent sulfur so that the brilliancy of the dyeings obtained in further increased.

Alkali metal hydrogen sulfites, especially sodium bisulfite, are employed as water-soluble salts of an oxygen acid of tetravalent sulfur; but also salts of pyrosulfurous acid, above all alkali metal hydrogen pyrosulfites such as sodium hydrogen pyrosulfite, can be used according to the invention.

As compounds which form stable, water-soluble, colorless complexes with detrimental metal ions, inorganic complex-forming compounds such as water-soluble polyphosphates or polymetaphosphates, preferably in the form of their alkali metal salts, and, still more preferably organic compex-forming compounds, especially basic nitrogen compounds are employed, which latter nitrogen compounds contain two unsubstituted or, optionally, substituted carboxymethyl groups bound to the nitrogen atom.

Such preferred organic basic nitrogen compounds are, for example, nitrilotriacetic acid, ethylenediamine tetraacetic acid, B-hydroxyethylethylenediamine triacetic acid, cyclohexylenediamine tetraacetic acid or diethylenetriamine pentaacetic acid, especially in the form of their Water-soluble salts, in particular their alkali metal salts. Other organic complex-forming substances as defined as, for instance, poycarboxylic acids containing hydroxyl groups such as citric acid or gluconic acid, also preferably in the form of their water-soluble salts. A preferred compound which is capable of forming stable, water-soluble, colorless complexes with metal ions is ethylenediamine tetraacetic acid preferably in the form of its water-soluble salts, such as its alkali metal salts, especially its triand/or tetranatrium salts, since the dye assistants containing the same impart to the deyings produced with their aid superior brilliancy and better color yields than are attained especially with the aforementioned inorganic complex formers.

Dyestuffs usable according to the invention are those which draw onto polyamide fibers, especially onto wool, and which are stable under the dyeing and bleaching conditions. Preferably such dyestuffs are referred to as being substantive to polyamides. These are technically readily accessible dyestuffs, for example, metal-free or heavy metel-containing monoazo or polyazo dyestuffs, anthraquinone, phthalocyanine, nitro, diphenylmethane, triphenylmethane or rhodamine dyestuffs.

Other auxiliaries which may be contained in the dyeing liquor are those conventional in the dyeing industry, especially acids when acid wool dyestuffs are used, also for example, wetting, leveling and dispersing agents, softeners which improve the handle, neutral and buffer salts, bactericides, fungicides and insecticides.

Natural and synthetic polyamide fibers, for example wool, silk and nylon, can be dyed by the process according to the invention. The polyamide fiber material can be used in this process in any form desired, for example, in the form of flocks, slub'bing, yarn or fabrics. The polyamide fiber material can also be dyed in the form of mixed fibers such as cellulose fibers mixed or encrusted with polyamides, particularly in the form of mixed fabtics of wool and polyester fibers such as cellulose acetate, cellulose triacetate and, particularly, polyterephthalic acid diol ester fibers, or polyacrylonitrile fibers.

The dye liquor to be used according to the invention should have a content of 0.1 to 1 g. per liter, more preferably of 0.4 to 0.8 g. per liter, of water-soluble salt of an oxygen acid of tetravalent sulfur and of 0.1 to l g.

per liter, or even higher, especially of 0.2 to 0.5 g. and optionally 0.3 g. per liter, of metal complex-forming compound as defined. When acid wool dyestuffs are used, the liquor should contain, as further auxiliary, a conventional acid agent such as acetic, formic or sulfuric acid. Advantageously, the exhaustion method is used for the simultaneous dyeing and bleaching process according to the invention, at temperatures of 55-95 C., but with sufficiently heat-stable dyes also at the boiling temperature.

Preferably, such dye liquors are prepared by adding to the aqueous dyebath containing the dyestufl a dyeing assistant which contains (a) a water-soluble salt of an oxygen acid of tetravalent sulfur as defined above, and

(b) the above-defined metal-complex forming compound preferably in a weight ratio of (a) to (b) ranging from 1:10 to :1, more preferably from 4:5 to 3:1.

It is one of the advantages of the dye assistants according to the invention that they do not substantially alter the pH of the dyebath to which they have been added, and thus do not require special readjustment of the dyebath pH. Neither should they have any substantial buffering effect on the dyebath. Moreover, these dye assistants do not create any specific occupational hazards to the dyer and thus do not make any special precautions necessary beyond those in conventional dyeing processes. The preferred dye assistant according to the invention contains an alkali metal bisulfite, such as sodium bisulfite, or an alkali metal hydrogen pyrosulfite, such as sodium hydrogen pyrosulfite, as water-soluble salt of an oxygen acid of tetravalent sulfur, and ethylenediamine tetraacetic acid, preferably in the form of its water-soluble salts, especially triand/ or tetrasodium salt of ethylenediamine tetraacetic acid as compound capable of forming water-soluble metal complex.

The dyeings obtained by the process according to the invention are distinguished by excellent purity and brilliancy. This is particularly the case with dyeings in delicate pastel shades (so-called baby colors).

The following examples serve to illustrate the invention. The temperatures are given therein in degrees centigrade. C.I. means Colour Index, Second Edition, 1956 (and later supplements thereto) published by the Society of Dyers and Colourists, Bradford, England, and The American Association of Textile Chemists and Colorists, Lowell, Mass, U.S.A.

Example I g. of previously wetted woolen yarn are introduced into a warm dye liquor (goods-to-liquor ratio 1:40) which contains,

(a) 0.6 g./liter of sodium bisulfite (with 62% active S0 content),

(b) 0.4 g./liter of technical ethylenediamine tetraacetic acid disodium salt (prepared from corresponding amounts of the free acid and sodium hydroxide),

(c) 0.5 g./liter of acetic acid and (d) 0.01 g./liter of the acid anthraquinone dyestuff produced as described in Example 1 of German Patent 1,090,355, added thereto in this order.

The bath is kept at this temperature for 10 minutes, then heated to 85 within 30 minutes and kept at this temperature for about minutes. The dyed goods are then rinsed with cold water and afterwards dried at about 60.

Brilliant, pure, delicate blue wool dyeings are obtained.

If in this example, the ethylenediamine tetraacetic acid disodium salt is not added then, with the same pro- (cedure, noticeably duller and generally more weakly colored dyeings are obtained.

If in this example, instead of the 0.6 g./liter of sodium bisulfite, 0.05 g./liter of sodium hydrogen pyrosulfite are used then, with otherwise the same procedure, dyeings of similar quality are obtained.

Good dyeings are also obtained by using 0.4 g./liter of tetrasodium ethylenediamine tetraacetate, mono 'sodiumnitrilotriacetate, sodium citrate, sodium tripolyphosphate, trisodium phosphate or sodium hexametaphosphate instead of the 0,4 g./liter of ethylenediamine tetraacetic' acid disodium salt and otherwise following the procedure given in the example.

Instead of woolen yarn, nylon yarn can be dyed as described in this example with the same result.

If instead of the dyestuff mentioned above, those mentioned in the following Table 1 are used and otherwise the procedure given in the example is followed, then good dyeings are also obtained in the shades given in Column 111 of this table.

TABLE 1 I II 1111 Shade on No Dyestuffs woolen yarn 2 The acid anthraquinone dycstuff described in Gteen.

Example 2 of German Patent 889,192. 3 Acid anthraruiiuonc dyestufl described in Ex- Do.

ample 1 of English Patent 736,187. 4 01. Basic Red 8 (45150) Red. 5 (1.1. Basic Violet 10 (45170). Red. 6 0.1. Acid Blue 83 (42060)... 7 Cl. Acid Blue 00 (42055) 8 2:1 chromium complex described in Example 2 Green 01' Swiss Patent 330,129. 9 Acid (lisazo dyestull: Di-(p-o:-:y-phcnyl)- Yellow dimethylrnctllane-bis-(fl-amino-phcnyl-lsulfonic acid)-estcr:;1(3-sulfophenyl)-3- incthyl-fi-amino-pyrazolei 10 Disazo dyestuil described in Example 5 of Orange.

French Patent 1,150,719. 11 Monoazo dycstull described in Example 2 of Red.

French Patent 1,308,280. 12 The acid dyestui'l described in Example 29 in the Red.

Table of Belgian Patent 574,446. 13 Acid anthraquinone dyestuil described in Ex- Blue.

ample 5 of German Patent 1,148,341.

Example 14 If instead of the 0.5 g./liter of 40% acetic acid given in Example 1, 0.5 g./liter of concentrated formic acid and 1.25 g./liter of calcined sodium sulfate are used and if instead of the dyestutf given, the acid anthraquinone dyestuff described in Example 8 of German Patent 631,518 is used and otherwise the procedure given in Example 1 is followed, then brilliant, pure blue wool dyeings are obtained.

Such dyeings are obtained on using the dyestufis given in the following Table 2 instead of the above anthraquinone dyestuif.

Example 17 If instead of the 0.5 g./liter of 40% acetic acid, 0.75 g./liter of sulfuric acid and 1.25 g./liter of calcined sodium sulfate are used and instead of the dyestufi given in Example 1, the dyestuffs mentioned in the following Table 3 are used and otherwise the procedure given in Example 1 is followed, then brilliant, pure wool dyeings are obtained having the shades given in Column III of this table.

Example 24 25 g. of previously wetted woolen yarn are introduced into a 40 warm dye liquor (goods-to-liquor ratio 1:40) which contains 0.6 g./liter of solid sodium bisulfite (with 62% active S content),

0.4 g./liter of technical ethylenediamine tetraacetic acid tetrasodiurn salt,

0.5 g./liter of concentrated formic acid,

1.25 g./ liter of calcined sodium sulfate,

0.01 g./liter of the acid anthraquinone dyestufi produced as described in Example 1 of German Patent 1,090,355, added thereto in this order.

The bath is kept at this temperature for minutes, then heated to the boil within minutes and kept at boiling temperature for about 60 minutes. The dyed goods are then rinsed with cold water and afterwards dried at about 50-60.

Brilliant, pure delicate blue wool dyeings are obtained.

If in this example, the ethylenediamine tetraacetic acid tetrasodium salt is not added then, with the same procedure, noticeably duller and generally more weakly colored dyeings are obtained.

If in this example, instead of the 0.6 g./liter of sodium bisulfite, 0.05 g./liter of sodium hydrogen pyr-osulfite are used then, with otherwise the same procedure, dyeings of similar quality are obtained.

Also nylon yarn can be dyed as described in this eX- ample with the same result, instead of woolen yarn.

If instead of the dyestuff mentioned above, those mentioned in the following Table 4 are used and otherwise the procedure given in the example is followed, then good dyeings are also obtained in the shades given in Column III of this table.

TABLE 4 I II III N0. Drycstufis Shade on woolen yarn The acid anthraquinone dyestufi described in Green.

Example 2 of German Patent 889,192.

Acid anthraquinone dyestufl described in Ex- Do.

ample 1 of English Patent 736,187.

0.1. Basic Red 8 (45150). Red

0.1. Basic Violet 10 (4517 0.1 Acid Blue 83 (42660) Cl. Acid Blue 90 (42655) Blue.

2:1 chromium complex described in Example 2 Green.

of the Swiss Patent 330,120

32--- Acid disazo dyestuii: Di-(p-oxy-phcnyl)dimethyl- Yellow metl1ane-bis- (2-amino phenyl l -sulfonic acid)- ester31-(3-sullophenyl)-3-methyl-5-aminopyrazole.

33.--" Disazo dyestuff described in Example 5 of the Orange.

French patent 1,150,719.

34.-- Monoazo dyestufi described in Example 2 of the Red.

French Patent 1,303,286.

35 The acid dyestufi described in Example 29 in the Red.

table of Belgian Patent 574,446."

36 Acid anthraquinone dyestufl described in Ex- Blue.

ample 5 of German Patent 1,148,341.

6 Example 37 A dye assistant is prepared as follows:

40 kg. of sodium pyrosulfite (S0 content or" 67% 15 kg. of disodium ethylenediamine-tetraacetate, and 45 kg. of calcined sodium sulfate are mixed, all. of which are dry and comminuted in a mixing drum.

The resulting product is ready to be added to conventional exhaustion dyebaths destined for dyeing with baby colors. It can also be stored in a closed container for years.

In a similar manner, the following mixed dye assistants are prepared:

Example 38 40 kg. of sodium pyrosulfite (S0 content of 67%), 20 kg. of a technical mixture of trisodium and tetrasodium ethylene diamine-tetraacetate [obtained from one mol of the free acid and 1.1 mol of aqueous sodium hydr-oxide solution (36 B.) and referred hereinafter for the sake of brevity as EDTA], and 35 kg. of calcined sodium sulfate.

Example 39 Kilograms Sodium bisulfite (S0 content of 60%) 50 Pentasodium diethylenetriamine-pentaacetate 25 Example 40 Sodium metabisulfite 4'0 EDTA 19 Oaloined sodium sulfate 41 Example 41 Disodium nitrilotriacetate 12 Sodium bisulfate 45 Calcined sodium sulfate 48 Example 42 Trisodium diethylenetriaminepentaacetate 23.5 Sodium pyrosulfite 40 Calcined sodium sulfate 36.5 Example 43 Disodium cyclohexanediaminetetraacetate 20 Sodium pyrosulfite 40 Calcined sodium sulfate 40 Example 44 Disodium 3 hydroxyethyl ethylenediaminetriacetate 16.5 Sodium bisulfite 45 Calcined sodium sulfate 43.0 Example 45 Trisodium citrate 13.5 Sodium pyrosulfite 40 Calcined sodium sulfate 46.5

Example 46 Sodium gluconate 12-0 Sodium metabisulfite 40 Calcined sodium sulfate 48 Example 47 EDTA 20 Sodium pyrosulfite 40 Sodium chloride 5 Oalcined sodium sulfate 35 We claim:

1. A process for dyeing and simultaneous bleaching of polyamide fibers comprising treating the material with a dye liquor which contains as essential ingredients Watersoluble dyestuil substantive to polyamides, a water-soluble alkali metal salt of an oxygen acid of tetravalent sulfur, an acidifying agent, and a compound selected from the group consisting of water-soluble alkali metal polyphosphates, water-soluble alkali metal polymetaphosphates, a basic nitrogen compound selected from the group of nitrilotriacetic acid, ethylenediamine tetraacetic acid, ,8- hydroxyethyl-ethylenediamine triacetic acid, cyclohexylened-iamine tetraacetic acid, diethylenetri-amine pentaacetic acid, and water-soluble salts of such basic nitrogen compounds and a polycarboxylic acid from the group of citric acid and gluconic acid and watersoluble salts of such acids.

2. A process as described in claim 1, wherein said dye liquor contains sodium bisulfite as the water-soluble salt of an oxygen acid of tetravalent sulfur.

3. A process as described in claim 1, wherein said dye liquor contains sodium hydrogen pyrosulfite as the watersoluble salt of an oxygen acid of tetravalent sulfur.

4. A process as described in claim 1, wherein said dye liquor contains a member selected from the group consisting of ethylenediamine tetraacetic acid and its watersoluble salts.

5. A process as described in claim 1, wherein said dye liquor contains an acid wool dyestufi" as the water-soluble dyestuff.

6. A dye liquor suitable as bath for the simultaneous dyeing and bleaching of polyamide fibers, which dye liquor contains:

(a) a sufiicient amount of water-soluble dyestuff substantive to polyamides for dyeing said fibers,

(b) from about 0.1 to 1 gram per liter of a watersoluble alkali metal salt of an oxygen acid of tetravalent sulfur,

(c) a compound selected from the group of watersoluble alkali metal poly phosphates, water-soluble alkali metal polymetaphosphates, a basic nitrogen compound selected from the group of nitrilotriacetic acid, ethylenediamine tetraacetic acid, fi-hydroxyethyl-ethylenediamine triacetic acid, cyclohexylenediamine tetraacetic acid, diethylenetriamine pentaacetic acid, and water-soluble salts of such basic nitrogen compounds and a polycarboxylic acid from 0 ca the group of citric acid and gluconic acid and watersoluble salts of such acids, and

(d) an acidifying agent.

7. A dye liquor as described in claim 6, wherein said water-soluble salt of an oxygen acid of tetravalent sulfur is sodium bisulfite.

8. A dye liquor as described in claim 6, wherein the compounds under (c) is a member selected from the group consisting of ethylene diamine tetraacetic acid and its water-soluble salts.

9. A dye liquor as described in claim 6, wherein the compound under (0) is the tetrasodium salt of ethylene diamine tertaacetic acid.

10. A dye liquor as described in claim 6, wherein the compound under (0) is the pentasodium salt of diethylene triamine pentacetic acid.

11. A dye liquor as described in claim 6 wherein the acidifying agent is formic acid.

12. A dye liquor as described in claim 6 wherein the acidifying agent is acetic acid.

13. A dye liquor as described in claim 6 wherein the acidifying agent is sulfuric acid.

References Cited UNiTED STATES PATENTS 2,308,021 1/1943 Munz 8-87 2,914,374 11/1959 Harris 252-188 2,947,657 8/1960 Peteri 16283 X OTHER REFERENCES Durrand, Belgian Derwent Abstracts, Jan. 24, 1964, Abstract of Belgian Patent No. 634,568, pp. 1 and 2 of Textile Section, 8/ 19.

Heerman, Technologic der Textilveredlung, 2 Autlage, Springer Verg, Berlin, 1926, p. 465, 8/82.

Munter, Amer. Dyestuff Rep., Jan. 28, 1935, pp. 40-47.

Schmitt, Amer. Dyestulf Rep., May 5, 1947, pp. 238 239.

DONALD LEVY, Primary Examiner. 

